include more rings in random testing

[nilesjohnson]

p-adics should be included, perhaps at "level 0"?

The following "level 1" rings are not included in sage.rings.tests:

• power series rings

• Laurent series rings

• multivariate power series rings (implemented in implement multivariate truncated power series arithmetic #1956)

• infinite polynomial rings

Also, it's not clear that "level n" testing occurs for n > 1; e.g. multivariate polynomial ring in 3 variables over Laurent series ring over finite field of size 29, etc.

Quotient rings are also not included, but should be. There are probably more to be included than this list indicates.

CC: @tscrim @slel @kliem

Component: algebra

Keywords: random testing, rings

Author: Frédéric Chapoton

Branch/Commit: 8df28fa

Reviewer: Michael Orlitzky

Issue created by migration from https://trac.sagemath.org/ticket/9777

[fchapoton]

comment:1

Here is a branch.

But is this still pertinent ?

---

New commits:

1d8ef50

more tests for rings

[fchapoton]

Author: Frédéric Chapoton

[fchapoton]

Commit: 1d8ef50

[fchapoton]

Branch: public/ticket/9777

[fchapoton]

comment:2

any opinion on the pertinence ?

[orlitzky]

comment:3

Is this doctest checking the right function?

+
+def padic_field():
+    """
+    Return a random p-adic field modulo n with p at most 10000
+    and precision between 10 and 100.
+
+    EXAMPLES::
+
+        sage: import sage.rings.tests
+        sage: sage.rings.tests.integer_mod_ring()
+        Ring of integers modulo 30029
+    """
+    from sage.all import ZZ, Qp
+    prec = ZZ.random_element(x=10, y=100)
+    p = ZZ.random_element(x=2, y=10**4 - 30).next_prime()
+    return Qp(p, prec)
+
+

In any case, it would be nice to avoid adding new tests that require a specific random seed. We're pretty close to making all testing random testing.

[tscrim]

comment:4

I am not sure how useful this is for catching bugs as we do (or at least should do) good test coverage within the individual files/rings themselves. However, I would follow @orlitzky's recommendation as I don't have a strong opinion on this.

[sagetrac-git]

Changed commit from 1d8ef50 to 63fa6a3

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

5d4db0a	Merge branch 'public/ticket/9777' in 9.4.rc2
63fa6a3	fix some doctests, and harden them

[fchapoton]

comment:6

ok, should be better now

[orlitzky]

Reviewer: Michael Orlitzky

[orlitzky]

comment:7

Thanks! Many of these tests can probably be removed later on, but it's nice to have this old ticket fixed in the meantime, especially in the likely event that we all forget about it for another decade.

[vbraun]

comment:9

Merge conflict

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

8df28fa

Merge branch 'public/ticket/9777' in 9.5.b0

[sagetrac-git]

Changed commit from 63fa6a3 to 8df28fa

[fchapoton]

comment:11

indeed a serious merge conflict. Needs another round of review, please

[orlitzky]

comment:12

Still OK.

[vbraun]

Changed branch from public/ticket/9777 to 8df28fa